1. Field of the Invention
The invention relates to a power control system and a power control method, and more particularly to the power control system and the power control method that can be applicable to various operation modes.
2. Description of the Prior Art
Currently, typical portable electronic devices such as notebook computers, tablet computers, personal digital assistants, video games, video cameras and so on, can transform a DC (direct current) signal of a voltage level to a DC signal of another voltage level (a DC/DC transformer for example), an AC (alternate current) signal to a DC signal (an AC/DC transformer), a DC signal to an AC signal (a DC/AC transformer for example), or an AC signal to another AC signal (an AC/AC transformer for example). The classification of the forgoing transformers of the AC or DC power control system is based on the current status of the induction-storage elements. If a switch element is controlled to reach a conduction status prior to a zero-current point, then the operation of the power system is defined as a continuous conduction mode (CCM). If the switch element is controlled to reach the conduction status right at the zero-current point, then the operation of the power system is defined as a boundary (or critical) conduction mode (BCM/CrM). If the switch element is controlled to reach the conduction status after a delay time posterior to the zero-current point, then the operation of the power system is defined as a non-continuous conduction mode (DCM).
However, none of the current power control systems can fulfill all of the aforesaid operation modes, and thus the instant power control system cannot be switched to a proper operation mode in correspondence to the load status. Thereupon, various disadvantages to the power control system would be inevitable, such as a high input peak current, high frequency switch loss, entrance of the low-frequency intermittent burst mode, bias in current waveform, occurrence of audio noise while in entering an audio frequency and so on. Hence, any improvement upon the conventional power control system is definitely welcome to the art.